Although injection molds are known that have core components capable of forming such interior features as sets of continuously extending interior threads, until now, withdrawal of interior core components from molds capable of forming interior threads has typically required several revolutions of relative rotation of the thread-forming components to disengage them from the newly formed interior threads. In essence, the technique principally used to withdraw the thread-forming core components has been to “unscrew” the thread-forming core components from the newly formed interior threads.
Requiring that mold core components be rotated (i.e., “unscrewed”) for withdrawal greatly complicates and renders more costly the design of molds—calling for the molds to be provided with gears and other small and costly drive components that are subject to wear and breakage as well as a need for proper continuing lubrication, periodic service and replacement, and attendant down time.
Although injection molds having collapsible core components of various types are known for use in the molding of some types of undercut interior formations, until now, known types of collapsible core components for use in injection molds have not been at all well suited for use in the formation of extensive sets of continuously extending, uninterrupted interior threads.
Although collapsible core assemblies are known that employ a plurality of relatively movable components, no collapsible core assemblies suited for use in injection molds are known that employ separate sets of relatively movable core components that include one set of relatively movable core components that principally pivot between operational and retracted positions, and another set of relatively movable core components that principally translate between operational and retracted positions.